(Getty Images | Illustration by Zimbio)Here at Zimbio, defining hotness is a science. So for the fifth year in a row, we've used facts and figures to determine which famous pairings have it all: Success, Attractiveness, Popularity, and Staying Power. Check out the full list through the links below.

Five years into tallying the 100 Hottest Celebrity Couples, we're still refining our process, trying to find the perfect means of calculating the scores and rankings at the heart of this massive undertaking. It's still not quite perfect. (We're already anticipating a few tweaks for finding next year's scores!) But the basic premise has stayed the same since year one: Score a very long list of celebrity couples on Success, Popularity, Attractiveness, and Staying Power, and rank them according to their totals.

So for the sake of our geekier readers, here's a brief explanation of what that entails. Obviously we aren't going to give away all the details, but this should pull back the curtain a little on how we do things. To make this easier to digest, it's been broken down by category.